Flushing and recharging of air conditioners and refrigerators has always posed problems with the inevitable discharge of a portion of the refrigerant gas. With the discovery of the harmful affects of releasing halogenated fluorocarbons to the environment, strict regulations have been enacted, particularly with regard to Freon-12, which is the most widely used refrigerant in automobile air conditioners and other small units of that type.
Refrigerant recovery systems have been constructed which minimize the discharge of refrigerant gas. Two such systems are shown in U.S. Pat. Nos. 4,476,688, issued Oct. 16, 1984, and 4,539,817, issued Sep. 10, 1985. Both of these systems include a condenser and a series of filters designed to liquify the refrigerant and to separate solid liquid impurities therefrom. In both systems, indeed in all prior recovery systems, careful attention must be paid to the operating conditions of the system to insure maximum performance and to prevent overloading and possible refrigerant gas leakage. Since the process is a relatively lengthy one, the constant attention required hinders the profitability of a service organization by tying up the mechanics, or worse, can be dangerous when left unattended by the mechanic who often has several other jobs to perform in a limited time. Further, the prior art systems could not be periodically checked to insure the effectiveness of the recovery, and were deficient at removing ambient air, a naturally occurring refrigerant gas contaminant, and oil contamination due to interaction of refrigerant with oil from the compressor pump.